MILLBURN — When Dianne Eglow was a kid living in Millburn, she enjoyed going to the South Mountain Reservation with her parents to feed the deer frolicking near the Rahway River.

When she became a parent she shared her love for the reservation with her children, taking them on bike rides and hikes through the nature oasis.

"You could kinda pretend you were in Vermont," she said. "It’s just this amazing place that is just always there."

So, Eglow and others in nearby communities were angered when they found out that the New York District of the U.S. Army Corps of Engineers is considering installing a dam more than 800-feet wide and 70-feet high on the South Mountain Reservation to prevent flooding, particularly in Cranford.

"I just think it would be an environmental disaster," Eglow said. "Everyone was shocked and outraged that this was even on the table."

But others say the dam and any other measure that could prevent homes from being damaged by a major rainstorm is worth studying.

"Do I think it’s a viable option? Most certainly," said Richard Marsden, the director of engineering in Cranford’s public works department. "I think for all of us to be honest, we have to look at that."

On Monday, the Corps in conjunction with the state’s Department of Environmental Protection discussed with nearby mayors 10 options to mitigate flooding of the Rahway River, four of which included the dam.

If chosen, it would be installed on the southern end of the reservation near Campbell’s Pond, to reduce the amount of water flowing into communities downstream, according to Corps public affairs specialist Chris Gardner.

Rough estimates for the project range from $115,724,100 to $164,005,100, according to the agency. It is likely federal authorities would pick up 65 percent of that tab, with the state and local municipalities sharing the rest, Garnder said.

On Tuesday, the Maplewood Township Committee passed a resolution opposing the dam proposal, and South Orange’s Board of Trustees passed a similar measure in late March.

Officials at the Corps and the DEP are still deciding which of the flood mitigation options to evaluate further.

But some residents are taking no chances. They have started a Save our Reservation organization, whose Facebook page had collected more than 2,300 ‘likes’ by Friday.

More than 3,300 people signed a petition on change.org opposing to the dam. On Sunday, the group plans to meet at the Millburn Public Library to discuss their next steps.

"This river valley would be destroyed by the dam," said Fred Profeta, a former mayor of Maplewood and chair of the Save our Reservation group.